U.S. Pat. No. 3,850,924, filed Apr. 5, 1973, by Julius J. Fuchs and Joel B. Wommack, and granted Nov. 26, 1974, discloses a process for making 3-cyclohexyl-1-methyl-6-dimethylamino-s-triazine-2,4(1H,3H)-dione by the following reaction sequence: ##STR1##
Copending U.S. Pat. application Ser. No. 895,587, filed Apr. 21, 1978 by C. D. Adams et al. discloses an improved process for making such triazinediones wherein significant increases in the practical yield are achieved by utilizing an alkyl chloroformate of the formula ##STR2## WHERE R = ethyl, n-propyl or isopropyl, in the first reaction step shown immediately above, and, of course carrying the corresponding alkyl substituent through the remainder of the reaction steps.
In the above-referred prior art processes, it was found that the triazine product underwent reaction with the alkanol produced by the cyclization reaction, which caused considerable loss in yield. This side reaction could be reduced to acceptable limits only by the addition of a large excess of dialkylamine to the cyclization reaction system. However, it has now been found that the side reaction can be suppressed by a more efficient and economical procedure, which requires no addition of dialkylamine or any other foreign material which must then be removed in the recovery of purified triazine product.